1. Field of the Invention
The present invention relates to jack stands. The present invention also relates to jack stands that support various diameters of pipes. More particularly, the present invention relates to jack stands that are adaptable so as to support the pipe above the ground at various levels so as to keep the working height comfortable for welders.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
Small, portable, generally triangular jack stands of been employed for many years for the temporary support of mechanical objects during construction or other working operations. Jack stands are particularly useful in the support and alignment of pipe, such as for positioning adjacent pipe sections and pipe fittings in precise alignment for welding operations. For the support of pipe, screw thread-type jack stands are typically provided with various types of support heads depending upon the construction operation that is to be accomplished. For example, one type of support head may take the form of a V-shaped cradle that receives the pipe to be supported. This type of object support is known in the industry as a “V-head”. Where the pipe is to be supported for rotation, a pipe support head having horizontally-arranged, spaced rollers may be employed. This type of object support is referred to as a “roller head”.
One particular type of jack stand is known as the “Hi-Low Screw Jack”. This jack stand incorporates a generally triangular base incorporating a vertically-oriented support tube. An elevation tube is received in telescoping relation within the support tube and may be manually raised or lowered to position the object support near its desired position. This adjustment may be referred to as a “coarse adjustment”. Thereafter, the jackscrew, which is located in telescoping relation within the elevation tube, is manipulated upwardly or downwardly to achieve precise positioning of the support head. This character of adjustment may be referred to as a “fine adjustment”.
Most high/low screw jack mechanisms employ a support tube of cylindrical configuration and also incorporate an elevation tube of cylindrical configuration being received in telescoping relation within the support tube. Typically, this type of jack mechanism incorporates a lock mechanism enabling the elevation tube to be secured in substantially immovable relation with the support tube. This type of lock mechanism is of a friction type and incorporates an externally threaded shaft that is received by an internally threaded receptacle of the support tube and is capable of being extended through an aperture in the support tube for frictional engagement with the outer cylindrical surface of the elevation tube.
The jack screw mechanism typically incorporates a drive nut that is received by the course of Acme threads of the jack screw and are rotatably adjustable relative to the jack screw. The drive nut typically defines opposed operating handles for rotation thereof relative to the jack screw. In operation, the drive nut simply rests on the upper extremity of the elevation tube so that rotation of the drive nut achieves vertical movement of the jack screw and the support head carried by the jack screw.
In certain circumstances where diameters of the pipe vary substantially, the prior art jack stands are incapable of allowing the welder to conveniently carry out the necessary welding activities. If a very large diameter pipe would be placed upon the support head of a conventional jack stand, the upper portion of the pipe would be outside of the range of the welder or, at least, difficult to reach by the welder. As such, it becomes difficult to conveniently position such a large diameter pipe for proper manipulation by the operator. Additionally, the location of such large diameter pipe on the support head at an elevated position greatly raises the center of gravity of the pipe. As such, can be possible for the jack stand and the pipe supported thereon to be toppled or unsteady. This can result in potential injury to the operator. Typically, the support heads are located in a fixed position and, as a result, cannot expand so as to more properly support the pipe in a stable configuration. As such, a need has developed so as to provide a jack stand that can be adapted so that large diameter pipe can be maintained in a proper position with a low center-of-gravity that can be conveniently worked by the welder.
In other circumstances, jack stands can have a relatively significant height. As such, they can become difficult to store and to transport. It is often desirable to store jack stands in a relatively small location or to conveniently transport such jack stands.
In other circumstances, very large jack stands may be required so as to accommodate large diameters of pipe. Where various diameters of pipe are being welded, the user must have one type of jack stand available for very large pipe and another type of jack stand available for smaller diameter pipe. As such, need has developed so as to provide a single jack stand that can be utilized for both smaller diameter pipe and for larger diameter pipe.
In the past, various patents have issued relating to such jack stands. For example, U.S. Pat. No. 3,741,509, issued on Jun. 26, 1973 to L. M. Kelly, describes a tripod type jack stand or support device. This tripod jack stand includes a camming means that functions, when activated, to maintain the legs in their folded side-by-side relation with the body of the jack stand. In particular, there is a plurality of legs that are pivotally attached to the barrel of the jack stand. A stationary V-shaped support head is utilized so as to receive the pipe therein. A pair of opposed rollers operate so as to allow the pipe to rotate within the interior of the V-shaped support head.
U.S. Pat. No. 3,602,492, issued on Aug. 31, 1971 to W. E. Petrie, describes a collapsible jack stand which includes an upright member and at least three legs secured to the upright member at the lower end thereof. The legs extend outwardly and downwardly therefrom below the lower end of the upright member. A flexible elongated chain connects the legs and the upright member to brace the legs with respect to the upright member. A work-holding device is mounted on the upper end of the upright member and a pair of arms diverge upwardly therefrom so as to form a generally V-shaped saddle for receiving a cylindrical workpiece. Roller assemblies are mounted on each of the support arms with rollers rotatable about parallel axes extending generally perpendicular to the plane of the V-shaped saddle to permit the cylindrical workpiece to be rotated about its axis while being supported on the rollers.
U.S. Pat. No. 5,165,665, issued on Nov. 24, 1992 to the present Applicant, shows an adjustable collapsible jack mechanism. This adjustable jack mechanism incorporates a base structure having a support tube and a plurality of angulated leg supports projecting radially therefrom so as to allow pivoting of the support legs in two positions parallel to the support tube. The plurality of support legs are pivotally connected to the leg support elements and are stabilized relative to the support by a support ring and pivotal support links. An elevation tube is telescopically movable within the support tube and is selectively locked relative thereto by a primary lock including a locking ring that is angulated by an external locking element for frictional gripping relation with the elevation tube. A jack screw is telescopically positioned within the elevation tube and is vertically adjustable by rotation of an adjustment nut for raising or lowering an object support provided at the upper end thereof.
U.S. Pat. No. 5,934,626, issued on Aug. 10, 1999 to R. H. Collins of the present Applicant, shows an adjustable pipe roll and support mechanism. This support mechanism has a round cross-sectional configuration and has a support base having a pair of parallel upright tubular members having rigid or collapsible support legs. Elevation posts are positioned in movable telescoping relation within respective tubular members and support a roll positioning head having an internal roll positioning mechanism. A pair of rollers assemblies are movably supported on the roll positioning head and in driven relation by the roll positioning mechanism and move toward one another away and from one another for selective positioning of the roller assemblies for rotatable support of ground objects of differing dimensions. The roller assemblies are connected to the roll positioning mechanism by quick disconnect mechanisms to permit the roll assemblies to be changed out to accommodate rotatable support of different types of objects.
U.S. Pat. No. 6,988,719, issued on Jan. 24, 2006 to Ursell et al., describes a stand for movably supporting a workpiece. The stand includes a base, a support and a plurality of roller assemblies. The support is releasably connected to the base for permitting the height of the stand to be altered. The roller assemblies are mounted on diverging surfaces which are, in turn, mounted at oblique angles relative to the support for permitting non-interfering movement of the workpiece relative thereto. Each roller assembly includes a sphere captured within a collar mounted on a selected one of the diverging surfaces for permitting free-rolling movement of the sphere relative to the collar and the workpiece.
U.S. Patent Application Publication No. 2008/0106018, published on May 8, 2008 to B. Bellavance, discloses a pivoting head for a welding stand. The pivoting head apparatus supports a cylindrical object having a longitudinal axis. The pivoting head apparatus comprises a base member and a support member pivotally mounted to the base member so that, in operation, the support member pivots about an axis that is generally perpendicular to the longitudinal axis of a cylindrical object. The pivoting head apparatus further comprises a plurality of rollers for rollably engaging the cylindrical members.
Canadian Patent No. 2,739,005, issued on Oct. 28, 2012, shows a workpiece support assembly. This workpiece support assembly includes a frame member, a first roller assembly having a first swing arm and a first roller rotatably mounted to the first swing arm, and a second roller assembly having a second swing arm and a second roller rotatably mounted to the second swing arm. Each of the first and second swing arms are rotatably mounted to the frame so as to form a space between the first roller and the second roller for receiving the workpiece in rolling contact with the first roller and the second roller such that the workpiece can be rotated about its axis while being supported by the first and second rollers. Each of the first and second swing arms are rotatable to selectively position the first and second rollers towards or away from each other so as to increase or decrease the space therebetween.
Chinese Patent No. 102500984, issued on Jun. 20, 2012, shows a welding lift frame that has a bracket. The upper end of the bracket is provided with a sleeve. A lead screw of a lead screw and nut mechanism is sleeved in the sleeve. The upper end of a lead screw of the lead screw and nut mechanism is provided with a supporting member. A nut of the lead screw and nut mechanism is arranged on the sleeve. The lead screw and nut mechanism can be used for adjusting the height of the supporting member so that the height of the workpiece can be adjusted at any time to facilitate the welding of the workpiece.
It is an object of the present invention to provide a jack stand apparatus and method that facilitates the ability to conveniently weld workpieces.
It is another object of the present invention to provide a jack stand apparatus and method that can accommodate different diameters of pipe.
It is another object of the present invention to provide a jack stand apparatus and method that adapts to the space requirements of the facility, workspace, or transport vehicle.
It is another object of the present invention to provide a jack stand apparatus and method that is smaller and more compact.
It is another object of the present invention provide a jack stand apparatus and method which is disassembleable.
It is a further object of the present invention provide a jack stand apparatus and method which can optimize the center-of-gravity of the workpiece and the jack stand.
It is a further object of the present invention to provide a jack stand apparatus and method which maximizes the height of the jack stand while minimizing the profile of the jack stand.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.